A conventional shredding machine may produce fragments of the feedstock which have different sizes. Fragment size is influenced by the size, shape and composition of components of the feedstock among other factors. The effect is most pronounced in instances where the feedstock includes components of greatly differing sizes, shapes and physical properties. The presence of relatively large fragments in the output of a shredder to some extent defeats the purpose of the shredding operation and in certain cases can have adverse effects on the further processing of the shredded material. The processing of infectious medical wastes, such as are generated at hospitals, medical clinics and the like is one example.
Infectious medical wastes may include used bandages and tissues, hypodermic needles, specimen containers, hard metal prostheses and diverse other objects and materials. Such wastes must be sterilized prior to disposal of the waste at a landfill, garbage dump or the like and it is advantageous if the waste is shredded following sterilization. Thorough shredding enables greater compaction of the waste and thereby reduces hauling costs and space requirements at the dump site. Potentially hazardous sharp objects in the waste are reduced to fragments. The shredded condition makes it apparent to handlers that the waste has been processed and rendered harmless and also makes it unrecognizable as medical waste by casual observers who might otherwise be needlessly apprehensive upon encountering such wastes. The presence of large fragments in the processed waste detracts from full realization of these objectives. A thin hypodermic needle, for example, can pass intact through a conventional shredder if it enters the mechanism at certain points in an end forward orientation.
The present invention is directed to overcoming one or more of the problems discussed above.